Fluid motor mechanism



June 15, 1954 E. E. SNACEK FLUID MOTOR MECHANISM Original Filed March 22, 1948 2 Sheets-Sheet 1 IN VEN TOR.

Patented June 15, 1954 FLUID MOTOR MECHANISM Emil E. Sivacek, Ann Arbor, Mich, assignor to King-Seeley Corporation, Ann Arbor, Mich a corporation of Michigan Original application March 22, 1948, Serial No.

16,271. Divided and this application December 20, 1950, Serial No. 201,825

The present invention relates to fluid motors and particularly relates to a fluid motor construction of the type embodying automatically operable reversing valve mechanism and having partioular utility for operating automobile windshield wipers.

This application is a division of my copending application on Fluid Motor Mechanism, Serial No. 16,271, filed March 22, 1948.

Principal objects of the present invention are to provide a fluid motor mechanism of the above generally indicated type which is simple in construction, economical of manufacture and assembly, which is reliable and efficient in operation; to provide such a mechanism embodying a casing of improved construction; and to provide in such a mechanism, a casing having improved silencing means incorporated therein.

With the above as well as other and more detailed objects in view, which will become apparent from a consideration of the accompanying drawings, the following description, and the appended claims, a preferred but illustrative embodiment is shown in the drawings, throughout the several views of which corresponding reference characters are used to designate corresponding parts and wherein:

Figure l is a view in side elevation showing a preferred. embodiment of the invention;

Figure 2 is an end view of the embodiment shown in Figure 1;

Figure 3 is an exploded view of the casing of the embodiment shown in Figure 1;

Figure 4 is an enlarged view in vertical transverse section taken along the line 4-4 of Figure 5; and,

Figure 5 is a partial View in longitudinal section taken substantially along the line 55 of Figure 4.

Although the fluid motor mechanism of the present invention has a particular utility when used for operating automobile windshield wipers it will be appreciated by those skilled in the art that in its generic aspects it has other uses within the scope of the present invention.

Referring to the drawings, the casing or housing it of the fluid motor there illustrated is generally cylindrical and comprises complementary center members I2 and M (Fig. 4), and cupshaped end members it and 58. The end members l6 and it are removably secured to the complementary members 12 and hi by a plurality of screws 2% which at the same time serve to maintain the complementary center members i2 and it in abutting relation. The center members are 2 Claims. (01. 181-33) located relative to each other and held in position during assembly by a longitudinally serrated dowel pin 22 having one end mounted in the center member !2 and the other end received in a complementary recess formed in the center member [4.

Referring to Figs. 4 and 5, the interior of the housing ii! is cylindrically shaped and slidably receives a piston assembly comprising a pair of spaced pistons 25 rigidly mounted on a connecting rack 26 by means of rivets 28. A motor output shaft 39 is journaled in the center member is of the casing is and is driven through a gear segment 34 mounted on a longitudinally serrated f portion adjacent inner end and continuously meshing with the rack 25. Accordingly, reciprocative movements of the piston assembly are translated into oscillatory or rocking movements by the output shaft 3%. In the illustrated embodiment, the output shaft 36 at its outer end is provided with a crank 36 which is adapted for connection to the mechanism to be operated by the motor.

The pistons 2t co-operate with the end members iii and it of the casing It to define chamber spaces 38 and 4!] between the pistons 25% and their respective end members. The space between the pistons 24 is continuously vented to atmosphere by passages 4-2 and l l formed in the complementary center members l2 and M, respectively, of the casing It. The passage t2 has an enlarged center portion 6% communicating with a similar and complementary enlarged center portion 453 in the passage M. A silencing or sound a deadening material 50, such as felt or other material, is disposed within the enlarged center portions 46 and 4S and is effective to greatly reduce the noise audible from the exterior of the motor, as well as to filter the air which passes therethrough.

It will be appreciated that reciprocation of the piston is effected by applying differential fluid pressures in the chamber spaces 38 and 4d. These diiferential pressures may of course be obtained from any suitable source. For example, in utilizing the present motor to drive an automobile windshield wiper system, the pressure differential may be the difference between atmospheric pressure and a sub-atmospheric pressure obtained in usual fashion by connecting the motor inlet stem 52 to the intake manifold of the associated engine. These differential pressures are communicated to the spaces 38 and til at opposite ends of the housing it by suitable passages communicating with the space between the pistons 2 4 and the stem 52, which passages are controlled by the manual control valve generally indicated at 70 and the automatic reversing valve generally indicated at 86 to provide the desired fluid circuits for operating and parking. These assages and valves 10 and 89 may be of any suitable design, the particular construction represented in the drawings being the same as that shown and described in greater detail in my above mentioned copending application Serial Number 16,271.

Although only a single embodiment of the invention has been described in detail, it will be appreciated that various modifications in the form, number and arrangement of the parts may be made Without departing from the spirit of the invention or from the scope of the appended claims.

What is claimed is:

1. In a fluid motor mechanism actuated by a pressure differential between atmospheric pressure and another pressure, a casing comprising complementary center members and end members secured to said center members, said center members being formed to provide passage means communicating at one end thereof with a portion of the interior of said casing and at the other end thereof with the exterior of said casing to at all times vent said portion of the interior of said casing to atmosphere, said passage means including an intermediate portion defining an enlarged chamber having complementary portions, one of said portions being formed in one of said complementary center members and the other of said complementary portions being formed in the other of said center members.

2. In a fluid motor mechanism actuated by a pressure differential between atmospheric pressure and another pressure, a casing comprising complementary center members and end mem bers secured to said center members, said cen ter members being formed to provide passage means communicating at one end thereof with a portion of the interior of said casing and at the other end thereof with the exterior of said casing to at all times vent said portion of the interior of said casing to atmosphere, said passage means including an intermediate portion defining an enlarged chamber having complementary portions, one of said portions being formed in one of said complementary center members and the other of said complementary portions beingformed in the other of said center members, and a sound deadening packing received in said enlarged chamber.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,774,376 Hueber et a1 Aug. 26, 1930 2,078,754 Day Apr. 27, 1937 2,218,719 Richards Oct. 22, 1940 2,385,084 Koppelman Sept. 18, 1945 2,484,548 Bitzer 1 Oct. 11, 1949 FOREIGN PATENTS Number Country Date 473,296 Great Britain Oct. 11, 1937 537,438 Great Britain June 23, 1941 817,517 France Sept. 4, 1937 

